CTA Assessment of Coronary Atherosclerotic Plaque Evolution after BVS Implantation – a Follow-up Study

Abstract

Abstract Background: Computed tomography angiography (CTA) occupies an important place in the evaluation of coronary atherosclerotic lesions, both before and after the implantation of bioresorbable stents (BVS), providing an accurate assessment of the treated lesions. Aim of the study: This study aims the prospective follow-up of atherosclerotic plaques electively treated with BVS implantation via CTA evaluation in terms of morphological and virtual histology aspects. Material and methods: This is a prospective observational study which enrolled 30 patients electively treated with BVS implantation, in whom CTA was performed after PTCA in order to assess the morphological and virtual histology aspects of coronary plaques. In order to evaluate the impact determined by pre- and post-implantation procedures, statistical analysis was performed among 6 subgroups. Results: After BVS implantation, a significant reduction was observed in terms of stenosis % (61.63 ± 12.63% in subgroup 1A vs. 24.41 ± 12.48% in subgroup 1B, p <0.0001) and eccentricity index (0.46 ± 0.24 in subgroup 1A vs. 0.43 ± 0.24 in subgroup 1B, p <0.0001). In terms of plaque components, there were significant differences with regard to lipid volume and lipid % (20.07 ± 15.67 mm3 in subgroup 1A vs. 11.05 ± 10.83 mm3 in subgroup 1B, p = 0.01), which presented a significant reduction after BVS implantation. The calcium score evaluated locally (82.97 ± 107.5 in subgroup 1A vs. 96.54 ± 85.73 in subgroup 1B, p = 0.25) and on the target coronary artery (148.2 ± 222.3 in subgroup 1A vs. 206.6 ± 224.0 in subgroup 1B, p = 0.10), as well as the total calcium score (377.6 ± 459.5 in subgroup 1A vs. 529.5 ± 512.9 in subgroup 1B, p = 0.32), presented no significant differences when compared with and without post-dilatation lesions. As far as CT vulnerability markers are concerned, the study groups presented significant differences only in terms of spotty calcifications (66.66% in subgroup 1A vs. 79.16% in subgroup 1B, p = 0.05) and low attenuation (37.5% in subgroup 1A vs. 20.83% in subgroup 1B, p = 0.01). Conclusions: Following the analysis of coronary artery plaques after the implantation of BVS, significant changes were noted both in the morphology of the atherosclerotic plaques treated with these devices and in the lumen and coronary wall.